Problem with iSCSI and WDS (Solved with DHCP route for iPXE User Class)

[ArneLovius]

The problem will not affect all installations.

If the site just had a router/L3 switch as the default gateway, then I think that as long as there was ICMP redirection on the router/L3 switch, the problem would not arise.

At my location, a Cisco ASA is the default gateway, a firewall rather than a router....

By adding to the iPXE user class (in the same way as for PXE Chain Loading) DHCP option 003 (Router) with the IP address of the iSCSI server, when iPXE writes the iBFT, the router/default gateway is set to the iSCSI server

This means that when Windows reads the iBFT and sets a static route to the iSCSI SAN/Server using the address that was the default gateway of the NIC in the iBFT, the gateway address for the iSCSI SAN/Server is the iSCSI SAN/Server, rather than in my case the Cisco ASA firewall...

As most iSCSI installations would have the iSCSI SAN/Server on the same subnet as the client, it might be worthwhile to document on the WDS iSCSI howto, setting this DHCP option using the iPXE User Class by default, adding the proviso "unless your iSCSI SAN/Server is on a different subnet"

The light bulb came on when reading this email in the mailing list http://lists.ipxe.org/pipermail/ipxe-dev...02117.html and having re-read it beyond where I stopped, it even says it explicitly :-)

If I had used sanbootconf I presume that I would not have experienced the problem, but there was no documentation to suggest that it was required on the WDS iSCSI howto when using Windows 7 or Windows Server 2008r2, which is where I started from.

The two IP addresses in the setupact.log were a red herring, they exist in the setupact.log of a completed install. Why it does it, I haven't got a clue...